Control mechanism



1951 R. o. BULLARD' ET AL CONTROL MECHANISM Filed Aug. 26, 1944 5m RA mu M E 2 m m m Patented Nov. 20, 1951 CONTROL MECHANISM Robinson D. Bullard, Greens Farms, and John H. Sherwood and Paul M. Geist, Fair-field, Conn.,

assignors to The Bullard Company,

tion of Connecticut a. corpora Application August 26, 1944, Serial No. 551,328

24 Claims. (01. 192-142) v This invention relates to-controls for apparatu capable of producing a relatively large number of functions. Particularly, it relates to a control mechanism that will automatically select, in any order within a cycle of operation, any one or more functions of which an apparatus is capable, while providing separate electronically-controlled means for very accurately determining the extent of said functions.

Objects of the invention include, the provision of apparatus for moving a member in space, and

an electronically-controlled means for accurately stopping the motion of the member at any point in space; the provision of apparatus for moving a member along one ormore paths, and an electronic circuit responsive to the arrival of the member at any pre-determined point in any of its paths for stopping the movement of the member; the provision of such an apparatus in which a member can be moved a plurality of times along the same path for different overlapping distances and separate portions of the electronic circuit are effective for each movement accurately to stop the member at any pre-determined point in its path of movement; the provision of an apparatus for remotely controlling the accurate stopping of the movement of a member; the provision of apparatus capable of performing a relatively great number of functions, a pre-settable device for selecting any of the functions successively within a cycle of operation and separate electronically-controlled means for each function of the cycle for starting the next succeeding function upon the completion of the last preceding function; the provision of electronically-controlled apparatus for remotely controlling the accurate movement of a member; the provision of a remotely-operable electronic servo-motor de-.

vice for causing movement of a member in proportion to the movement of a remotely-operable control therefor; and the provision of a machine tool including a turret tool support, a work support, and means for moving one of said supports in either direction, along a plurality of paths at a plurality of speeds and a control for selecting the path, direction and speed of movement of the movable support for performing successive functions within a cycle of operation, including electronically-controlled means for each function in the cycle for causing the control to start the next succeeding function at the completion of the last preceding function.

The above, as well as other objects and novel features of the invention will become apparent from the following specification and accompanying drawing, in which:

The figure is a schematic layout of the essential features of the invention.

Referring to the drawing, the invention is shown as applied to certain parts of a vertical turret lathe including a cross rail C along which a saddle S is adapted to be moved. The saddle S supports a slide including a turret head H for movement at right angles to the movement of the saddle S along the cross rail C. The turret head H isadapted to bemoved along the two right-angular paths relatively to a work support (not shown) by the selective operation .of a feedworks transmission T. A function control F is adapted to be pre-set for causing the transmission T successively to move the head H along either of its paths of motion at any desired speed and in either direction to perform a cycle of operation. An additional control comprising an electronic circuit E is provided for accurately stopping the movement of the head H when it has arrived at the desired point in its paths of travel and for causing the control F to start the next succeeding function of the head H within the cycle of operation at the completion of the preceding movement of the head'H.

The cross rail C comprises spaced, horizontallydisposed bearings l0 and l I along which the saddle S is adapted to be moved. The saddle S comprises a body I2, to the back of which a threaded boss I3 is fixed that receives an axially-fixed screw 14. Accordingly, rotation of the screw 14 in either direction causes movement of the saddle I2 in either direction along the bearings l9 and II. A slide 15 is mounted between bearings 16 and H on the saddle 12 for movement at substantially right angles to the movement of the saddle l2 along the cross rail C. A bevel gear i8 is splined to a rotatable, axially-fixed shaft is. Gear I8 is fixed to the saddle l2 for movement therewith and meshes with a gear unit including a bevel gear 20. The gear unit also includes a spur gear 2| which meshes with a rack 22 on the back of the slide l5. Accordingly, rotation of the splined shaft 19 in either direction causes the head H to move along the bearings it and ill of the saddle l2.

Rotation of the screw [4 and the splined shaft I9 is accomplished by the operation of the transmission T. The transmission T includes a shaft 23 that is driven by means which drives the work support of the apparatus (not shown) in the same way that the work support is driven in application Serial Number 541,986 filed June 24, 1944 in the name of Edward P. Bullard, III, now Patent No. 2,528,736, issued Nov. 7, 1950. The shaft 23 supports two bevel gears 24 and 25 for free rotation. A clutch 26 is located between the gears 24 and 25 and is splined to the shaft 23. Both gears 24 and 25 mesh with a bevel gear 21 fixed to a shaft 28. Spur gears 29 and 38 fixed to shaft 28 mesh with corresponding spur gears 3| and 32, journaled on a shaft 33. The shaft 33 is hollow for receiving a diving key 34. The key 34 is adapted to be moved from engagement with the gear 3| to engagement with the gear 32 selectively for a purpose to be described later. Spur gears 35, 36, 31 and 38 are fixed to the tubular shaft 33 and mesh with corresponding spur gears 39, 48, 4| and 42 journ'aled on another shaft 43. The portion of shaft 43 on which the gears 39 to 42 are journaled is of tubular construction for receiving a diving key 44. A bevel gear 45 is fixed to shaft 43 and meshes with a bevel gear 46, fixed to a worm 41. A worm gear 48 is fixed to the splined shaft I9, and a similar worm gear 49 is fixed to the screw I4. Accordingly, it is evident that worm 41 may be rotated in either direction at any one of eight different speeds, depending upon the positions of the diving keys 34, 44 and the clutch 26. Furthermore, the head H can be moved in either direction along either of its paths of motion by raising or lowering the worm 41 into engagement with the worm gears 48 or 49.

A housing 58 is attached to the end of the cross rail C opposite that which supports the feedworks T. This housing is adapted to support continuously-driven, oppositely-rotatable means adapted to be connected to, and disengaged from the screw I4 and the splined shaft I9 through the selective operation of rods and 52. Crank arms 53 and 54, having hand levers 55 and 56 are provided for operating rods 5| and 52. This construction provides means for moving the turret head H along either of its paths at a relatively fast traverse speed. Crank arms 53 and 54 are also adapted hydraulically to be actuated by pistons within cylinders 51 and 58. The pistons within these cylinders are connected to the arms 53 and 54 by connecting rods 59 and 68.

The worm 41 is adapted manually to be moved into and out of engagement with the gear 48 and 49 by a hand lever (not shown), fixed to a connecting rod 6|. The connecting rod BI is attached to a piston within a cylinder 63. The clutch 26 is adapted manually to. be moved by a hand lever 64 through anarm 65. The arm 65 is connected to a rod 66 that is attached to a piston within a cylinder 61. The piston and cylinder mechanisms 51, 58, 63 and 61 are identical with corresponding cylinder and piston mechanisms for moving the identical parts shown in application Serial No. 541,986 filed June 24, 1944, in the name of Edward P. Bullard, III, now Patent No. 2,528,736. 4

The cylinder 58 includes a dividing partition 18 that cooperates with an end 1| to provide a cylinder for a piston 12. The piston 12 includes a rod 12' that extends throughthe partition 18 and a rod 12" that extends through the end portion H. The rod 12' is reduced in diameter and passes into another portion of. the main cylinder 58. Oppositely-disposed discs 13 and 14 are mounted on the rod 12' for free movement relatively thereto. A nut 15 is screwed onto the end of rod 12' in abutting relation with disc 14. The disc 13 abuts against the shoulder formed between the rod 12' and its reduced diameter portion. It also abuts against the partition 18. Fluid under pressure is adapted selectively to be admitted to opposite faces of the piston 12 through conduits 16 and 11. Pressure is at all times adapted to be supplied through a conduit 18 t the cylinder containing the discs 13 and 14. The efiective pressure area of the discs 13, 14 is less than the efiective pressure area of the piston 12. Consequently, admission of pressure to the cylinder 58 through the lines 16 and 11 will cause the piston 12 to moveoivithin the cylinder 58. Removal of pressure from both line 16 and 11 will effect the instantaneous centralization of the piston 12 t in the cylinder 58. This construction provides means for positively moving the crank arm 54, and identical mechanism is employed to move arm 53, clutch 26 and worm 41 to their active positions and causes neutralization of these elements upon removal of the pressure from the corresponding pistons thereof.

The diving key 34 is adapted manually to be moved by a hand lever 68, while the diving key 44 is adapted manually to be moved by a hand lever 69. These keys are adapted hydraulically to be actuated by cylinder mechanisms 19 and 88. The cylinder mechanisms are identical with the corresponding mechanisms shown and described specifically in the above-referred-to application Serial Number 541,986. Fluid under pressure admitted to line 8| alone will cause key 44 to engage gear 42; fluid under pressure admitted simulta neously to the conduits 8| and 83 will locate the key 44 in engagement with the gear 4| simultaneous admission of fluid under pressure to the conduits 84 and 82 will cause the key 44 to engage the gear 48; and admission of fluid under pressure to the conduit 84 alone will locate the key 44 in engagement with the gear 39.

The cylinder 88 is provided with two conduits 85 and 86. Admission of fluid under pressure to the conduit 85 positions key 34 in engagement with gear 32; while release of pressure from conduit 85 causes key 34 to become engaged with gear 3|, all as more fully disclosed and described in application Serial No 541,986, above referred to.

Fluid under pressure is adapted selectively to be supplied to the piston mechanism 61 through a conduits 81 and 88. Fluid pressure is adapted to be supplied to the piston mechanism 51 through conduits 89 and 98. Fluid under pressure is adapted to be supplied to the piston mechanism 63 through the conduits 9| and 92. Fluid under constant pressure is adapted to be supplied to piston mechanisms 61, 51 and 63 through conduits 93, 94 and 95, respectively. This constant pressure fluid is supplied to the conduits 93, 94 and 95, as well as to the conduit 18 by a line 96 that leads from a main source of fluid supply P through a duct 91 and a valve 98.

Conduits 16, 11, BI, 82, 83, 84, 85, 81, 88, 89, 98, 9| and 92 are adapted to be supplied with fiuid under pressure from the main source P through line 91, the valve 98 and a line 99. The line 99 is connected to an elongated valve body I88, that is provided with a centrally-disposed, longitudinally-extending passage I8I throughout its entire length. Valve body I88 is also provided with a plurality of transversely-disposed valve chambers of identical construction within which are located valve plungers I82 to H4, inclusive, for the conduits 16, 11, 8|, 82, 83, 34, 85, 81, 88, 89, 98, 9| and 92. The construction and operation of the valves I82 to H4 are identical with corresponding valves in the above-referred-to co-pending application, to which application reference is directed for details of construction. Suffice it to say that depression of any of the valves I82 to I I4 will permit fluid under pressure ,m the conduit m to responding conduits I6, 11, 8i, 82, 83, 84, 85,

be admitted to the corinstantaneous exhaust of all of the piston mech-' anisms 51, 58, 61,33 upon the completion of a motion of the head H, an exhaust valve mechanism I I9 is provided that operates in an identical manner with corresponding exhaust mechanism shown, described and claimed in the abovereferred-to co-pending application. Suffice it to say that fluid under pressure from the conduit 99 normally urges all of the piston mechanisms within the device II9 to the right, as viewed in the drawing, and upon the completion of any movement of the head H, all of these piston devices will be moved leftwardly, as will be described later.

The valves I02 to H4, inclusive, are adapted selectively to be depressed by the action of adjustably-mounted dogs on a drum I20 that is adapted to be indexed step-by-step about a horizontal axis, all as more fully disclosed and described in the above-referred-to co-pending application. The drum I20 is adapted to be indexed a pre-determined number of degrees about its horizontal axis intermittently so that the dogs located in a longitudinally-disposed row of open-' ings on the drum will become effective to depress selected valves I02 to H4. Thus, the drum I20 is made up of a plurality of portions each comprising one of the longitudinally disposed rows porting drum I20 for indexing the drum I20 from station to station. The ratchet wheel I2I is provided with a pluralit of circumferentiallydisposed ratchet teeth adapted to cooperate with a pawl I22 fixed to a reciprocable piston I23. The cylinder within which piston I23 is adapted to be reciprocated is connected to the line 97 at its one end, and to a line I24 at its other end. Fluid from source P is adapted to pass through a valve mechanism I25, a conduit I26, a valve IT! to the line I24. The effective area of the piston I23 that is affected b the fluid from duct 91 is substantially less than the eifective area affected by the fluid from line I24. Accordingly, although constant pressure from the line 9! always urges piston I23 upwardly, as shown in the drawing, admission of fluid under pressure to the line I24 will cause the piston I23 to move downwardly, whereupon the pawl I22 will index the ratchet I2I so that the drum I20 is moved from its one station to its next succeeding station thereby to initiate a succeeding pie-determined function of the head H.

The valve I25 includes two balls I28 and I29 joined by a slender rod I30. The unit including the two balls I28 and I 29 is normally urged righ"- wardly, as viewed in the drawing, by a spring i3I. Movement of the unit including the balls I28 and I29 to the left is effected by the energization of a solenoid I 32 to be described later. Upon movement of the balls I28, I29 to the left, fluid under pressure from the source P is adapted to flow through the line l20 to the valve I27, thence to the line 1120 to the upper end of the cylinder including the piston H23, thereby causing the downward movement of piston I23 and the indexing of the ratchet I2I and with it drum I20. A line I33, extending from the line I26, is

connected to the end of valve mechanism ,II9 opposite that to which line 99 is connected. Accordingly, upon energization of solenoid I32, the valve mechanism II9 is'actuated independently of the indexing of the drum I20. This operation of the valve mechanism actually occurs prior to the indexing of drum I20 and instantly upon the head H arriving at a pre-determined position incident to the function just completed. Accordingly, instantly upon valve mechanism II9 being actuated, all of the piston mechanisms 61, 51, 63 and 58 are exhausted and neutralized by their constant neutralizing pressure mechanism.

That which has been described comprises selectively-operable mechanism for causing the head H to produce any function of which it is capable in accordance with the operation of the valves I02 to H4. The extent of any function selected by the drum I20, or the stopping of the head at predetermined points in its paths of travel is adapted to be determined by mechanism associated with the movable head H. This mechanism is designed to provide a separate function-determining means for each function called for by the setting of dogs along a longitudinally-disposed row of openings on the drum I20. It comprises an electronic variable impedance bridge circuit and in the present embodiment, an electronic circuit including a variable capacitance bridge is shown and described.

A source of alternating current I34 at audio frequency is connected across a capacitance bridge I35 including four legs. Legs I36 and I31 of the bridge I35 include resistances R1 and R2 of equal value. The leg I38 of the bridge I35 is adapted to include either one of two variable impedances as for example plate-type condens ers I39 and I40. Condenser I39 is operated in response to the movement of the saddle S along the bearings I0 and II of the cross rail C, while condenser I40 is adapted to be operated in response to the movement of the head H and slide I5 along the bearings I6 and H in the saddle I2. The condensers I39 and I40 are adapted selectively to be connected into the leg I38 of the bridge I35 through a switch I4I. Switch MI is normally urged in a direction to include condenser I39 into the circuit of the leg I38, but when a dog on the drum I20 cooperates with the switch Hi, the condenser I39 is cut out of the circuit and the condenser I40 is connected into the leg I38 of the bridge I35. The final leg I42 of the bridge i35 includes a plurality of separate impedances and in the present embodiment they comprise condensers I43 to I50, inclusive, so that each may selectively be connected into the leg I42 by means to be described later. The conductor I5i that is common to one side of each of the condensers I43 to I50 is connected to the leg I42, while the opposite side of each of said condensers is connected respectively to contact points I to 8, inclusive, of a distributor I52. The distributor I52 includes an arm I53 that is fixed to the shaft on which the drum I20 is fixed. Accordingly, arm I53 is indexed step-by-step simultaneously with the indexing of the drum I 20. Although only eight contacts are shown on the distributor I52 corresponding to eight longitudinally disposed, peripherally arranged rows of openings on the drum 1129 for receiving the dogs that operate the valves E02 to lid, it is to be understood that any number of such contacts and rows of holes on drum I20 may be employed. In practice, it has been found that about forty such contacts on distributor I52 and longitudinally-disposed rows of holes on drum I20 are adequate for performing a cycle of opera tion necessary to complete the machining of an ordinary, relatively complex work piece.

A conductor I54 leads from the source of audiofrequency alternating current I34 to the bridge at a point between the condensers I39, I40 and the distributor I52. The other conductor I55 is connected to the bridge I35 between the resistances R1 and R2. At the junction between the legs I42 and I31 of the bridge I35, a conductor I56 is provided that extends to the one side of a primary coil I51 of a transformer. The opposite side of the primary I51 is connected to the bridge I35 between the legs I36 and I38.

The condenser I39, as previously mentioned, is of the plate type, the capacity of which is varied by a 180-degree rotation of its movable plates. Condenser I39 is fixed to the cross rail C and .is provided with a worm gear I58 fixed to the shaft on which the movable plates of the condenser I39 are attached. The gear I58 meshes with a rotatable, axially-fixed gear I59. A shaft I60 is connected to the saddle S by a bracket I6I. n the periphery of shaft I60, a spiral groove I62 is formed. The lineal extent of groove I62 is equal to the travel of the saddle S along the bearings I0 and II of the cross rail C. The angular disposition of groove I62 covers 180 degrees from its one end to its other end. The axially-fixed rotatable gear I59 is provided with a key number (not shown) that extends into the groove I62.

The construction and arrangement of the parts are such that upon movement of the saddle S along the bearings I0 and II of the cross rail C, the groove I62 will impart a rotary movement to the gear I59 of 180 degrees throughout the maximum travel of the saddle S. This 180 degrees of rotation of the gear I59 will cause 180 degrees rotation of the gear I58 and consequently, the movable plates of the condenser I39.

The condenser I49 is intended to be operated in response to the movement of the head H along the saddle I2. Accordingly, the condenser I40, which is identical with the condenser I39, is mounted on a bracket I63 fixed to the saddle I2 so that the condenser I will move with the saddle. The condenser I40 is also provided with a gear I64 that meshes with a gear I65. The assembly is fixed relatively to the saddle I2. Ashaft I66, having the same form of spiral groove I61 as groove I62 in the shaft I60, is fixed to the slide I5 by a bracket I68. Accordingly, movement of the slide I5 and the head H for its maximum distance along the bearings I6 and I1 of the saddle I2 causes the gear I to rotate through 180 degrees, thereby effecting 180 degrees movement of the movable plates of condenser I40.

The condensers I43 to I50 inclusive, are of the variable plate-type identical with, and each possesses the same capacity range as the condensers I39 and Ho. The condensers I43 to I50 inclusive, are adapted selectively to be pre-set to any desired capacity. Accordingly, when the arm I53 of the distributor I 52 engages any of the contacts I to 8 so as to include any of the condensers I43 to I50 in the leg I 42 of the bridge I35, an unbalanced or balanced condition will be set up in the bridge I35 depending upon the position of the movable plates of the condenser I39 or I40, whichever is in the circuit of leg I38, and consequently upon the location of the head H. In the event an unbalanced condition 'ex-' ists in the bridge I35 by virtue of the condensers in the respective legs I38 and I42 being out of balance, a pre-determined voltage will appear across the primary I51 of the transformer. When the condensers that are connected into the circuit of legs I38 and I42 of the bridge I35 are in perfect balance, the voltage across each of the condensers will be the same. Since R1 equals R2, and both condensers are charged by the same frequency, they will both have the same impedance. Accordingly, the voltage across the resistances R1 and R2 will be equal and there will be zero voltage across the primary I51 of the transformer. When an unbalanced condition exists in the bridge circuit by virtue of the condensers in the respective legs I38 and I42 having different capacities due to the unbalanced condition of their movable plates, a pre-determined voltage will appear across the primary I51 of the transformer which will be induced into the secondary I60 of the transformer. The secondary I69 is connected to an amplifying unit I10 which is adapted to amplify any small change in voltage induced in the secondary I69 of the transformer. This amplified change in control voltage is fed to a tube I1I that is operated as a biased detector. When a control voltage is impressed on the grid of the tube I'II, it draws current which energizes a solenoid I12 of a sensitive relay connected into its plate circuit. This flow of current extends from the source I15, that is grounded at I16, through solenoid I12 of the sensitive relay, thence through conductor I14 that leads to the plate of the tube I1I, thence to the cathode of said tube, to a ground I13. Adjustment of either of the condensers I39 or I40,

whichever is connected into the leg I38 of the bridge I35, by the movement of the head H along either of its paths of motion to a point where its capacitance equals that of the condenser I43 to I 50 that is connected into the leg I42 of the bridge I35, causes the bridge I35 to become balanced and no voltage is impressed upon the primary I51 of the transformer. Accordingly, the control voltage is eliminated from the grid of the tube HI and current ceases to how through the solenoid I12, whereupon a'spring I11 closes switch I18. The switch I18 includes two sets of contacts I19 and I80. permits current to flow from a ground I8I through the solenoid I32, generator G, a conductor I82 to a normally-closed switch I83, and thence through the closed contacts I19, a conductor I84, the normally-close contacts I85 to a ground I86. Energization of the solenoid I32 will cause leftward movement of the valve I25 thereby permitting fluid under pressure to pass through the conduit I26 to the valve I 21 and the line I33 to the valve mechanism I I9. Operation of the valve mechanism II9 will immediately neutralize the iston mechanisms 61, 51, 63 and 58. Flow of fluid through the valve I21 and the line I24 causes downward movement of piston I23 and indexing of the function drum I20. Indexing of drum I20 causes indexing of the distributor arm I53 to its next succeeding contact. As the arm I53 leaves the contact with which it was engaged, an unbalanced condition in the bridge I 35 will be created and, unless provision is otherwise made, current will be permitted to fiow through the solenoid I 12, thereby opening switch I19 before the drum I20 and the distributor I53 have completed an indexing movement. To overcome this condition, the contacts I are provided in the Closing the contacts I19 switch I18. Closing the contacts I88 short-circuits the solenoid I12 so that the unbalanced condition will cause the current to flow from the ground I 18, through the source I15, thence through'a conductor I81, normally-closed switch I88, another conductor I89, closed switch I80, conductor I14, tube I'1I to the ground I13. Accordingly, the unbalanced condition of the bridge I35 due to the arm I53 moving off one contact into engagement with the next, has no effect on the switch I18. At the end of the downward movement of piston I23, switch I83 is caused to be opened in the same manner as the corresponding switch in the application Serial No. 541,986, above referred to. Opening the switch I83 deenergizes the solenoid I32, whereupon the spring I3I returns valve I25 to its normally-closed position, cutting off the flow of fluid under pressure to the line I24 and permitting the pressure from line 91 to move the piston I23 upwardly, re-setting it and switch I83 for the next succeeding indexing function. Additionally, at the end of the downward movement of piston I23 a cam I98 effects opening of the normally-closed switch I88, thereby re-introducing the solenoid I12 into the plate circuit of the tube I1I whereupon said solenoid is energized by virtue of the unbalanced condition of the bridge I35, thereby opening the switch I18. Switch I18 then remains open until the head H has moved in the direction determined by the next succeeding setting of the dogs on the drum I20 and until the selected condenser I39 or I40 has moved to a position where its capacity equals that of the condenser I43 to I50 that has been included into the leg I42 of the bridge I35 by the last indexing movement of the arm I53. When this occurs, solenoid I32 is again energized to effect the next indexing of the drum I20 and the distributor arm I53.

The head H includes a turret I9| that is adapted to support a plurality of tools for movement into and out of engagement with work. The turret I9I is mounted for rotation on a stud I92 fixed to the slide I5. Normally, the turret I9I is rigidly locked to the slide I5, but it is adapted to be released and indexed from station to station by a motor I93 fixed on the slide I5, all in the manner shown and described in application Serial Number 443,992, filed May 21, 1942, in the name of Edward Bullard, III, et til, now Patent No. 2,384,809, issued September 18, 1945. The turret I9I is adapted to be controlled from the function drum I28 by a double pole switch I94 in the same manner as the turret is operated in application Serial Number 541,986, filed June 24, 1944, in the name of E. P. Bullard, III, now

Patent No. 2,528,736, issued November 7, 1950. Sufiloe it to say that closing switch I94 effects indexing of the turret I9I from one position to the other. it the conclusion of this turret index, function drum I20 is indexed to its next succeeding position and the turret driving motor I93 is re-set to provide another indexin movement of the turret I9I when called upon to do so by a dog on the drum I20.

Often, the work to be performed by the machine utilizes less than the total number of longitudinally-disposed series of holes about the drum I20, and before a. succeeding cycle of operation may be performed, the drum I 28 must be indexed back to its starting position. This is accomplished by providing a switch I95 in line with one of the circumferentially-disposed series of holes in the drum I20. The one pole of switch I95 is grounded, while the other pole is connected to a conductor I98, which latter is connected to conductor 2 I0, thence through switch I83, conductor I82 leading to the source of energy G. Closing a of the switch I95 by a do on the drum I28 will cause energization of the solenoid I32 to move the valve I25 to index the drum I20 to its next succeeding position.

The machine to which this control mechanism is applied is adapted manually to be operated independently of the automatic control. Furthervmore, during the setting up of the machine, it is desirable to cause it to stop at the completion of any function. Additionally, in the event anything occurs which might damage the machine, it is desirable to stop the machine instantly. These three conditions, as well as a fourth condition of automatic run, are each rendered effective by the operation of a single, manuallyoperable control lever I91 fixed to a shaft I98 that extends through the valves 98, I21 and a cam I99, all of which include portions fixed to the shaft I98. In the position shown in the drawing, the handle I91 is set for automatic run such that a cycle of operation set up on the drum I20 will automatically be performed by the successive indexing of the drum I28, which latter occurs only upon the com letion of the last.pre ceding function. The extent of each function is determined by the adjustment of the condensers I43 to I58, inclusive. Movement of the hand lever I91 to the position 200 will move the valve I21 to interrupt the communication between lines I26 and I24. Upon the completion of the function being performed when the handle I 91 is moved to the position 200, energization of the solenoid I32 will operate the valve I25 to neutralize the operating structure of the transmission T, but the drum I28 will not be indexed due to the interruption of the flow of fluid under pressure from the line I26 to the line I 24. Movement of the hand lever I91 to the position 20I will cause the cam I99 on the shaft I98 to close a switch 202. One pole of the switch 282 is grounded, and the other pole is connected to the conductor I82 leading to the generator G. Upon closing the switch 202, the solenoid I32 is instantly energized, operating the valve I25 and instantly stopping the movement of the head H without indexing the drum I20.

Movement of the hand lever I91 to the position 203 operates the valve 98 so that line 96 is exhausted through an undercut portion 204 of the valve 98 leading to an exhaust port 205. This exhausts all the neutralizing mechanisms including that for the clutch 28, the drop worm 41, and the traverse arms 53 and 54. It also exhausts the line 99 such that all of the valve plungers I82 to H4 descend out of operative position. Accordingly, the drum I20 may be indexed without causing operation of the transmission T. Additionally, movement of the handle I91 to the position 203 will operate valve I21 so that communication will be re-established between the lines I20 and I24.

The switch including contacts I also includes normally-open contacts 206 that are closed upon movement of the hand lever I91 to the position 203. One terminal of the contacts 206 is connected to a conductor 281 that leads to the line L2, while another conductor 208, connected to the other side of the contacts 286, is connected to one terminal of a push-button switch 289, the other terminal of which is connected to the motor I93. Accordingly, with the hand lever I91 in the position 283, the operator may at any the will of the operator.

11 time effect indexing of the turret I9I by simply closing the push-button switch 209.

The switch including contacts I85 also includes contacts 2I0 that are normally open, but which are closed by movement of handle I91 to the position 203. The one terminal of contacts 2| is connected through a conductor 2 to one side of a push-button switch 2I2, the opposite side of which is connected to the ground I86. The other terminal of contact 2") is connected to a conductor 2I0 that leads to the side of contacts I19 nearest switch I83 so that current flowing through contacts 2I0 must also pass through switch I83. Accordingly, with the hand lever I91 in the position 203, closing of the push-button switch 2-I2 will eifect indexing of the function drum I20 at However, since the line 96 is exhausted through the valve 98 when the hand lever I91 is in the position 203, indexing of the drum I20 by closing push-button switch 2I2 will cause the transmission T to produce no function.

An arm 2 I3 is connected to the shaft that supports the arm I53 of distributor I52, and is indexed in a step-by-step manner with arm I 53. A contact M5 is located such that the arm 2I3 engages it when the arm I53 is at the zero position on distributor I52. In other words, when the arm I53 of distributor I52 is at its starting position between the contacts for the last function and the first function of the cycle of operation, arm 2I3 engages contact 2I5. At no other rotary position of the arm 2 I3 will it engage contact 2I5. The contact 2I5 is connected to a conductor 2I6 that is attached to one pole of a pushbutton switch 2II, the opposite pole of which is attached to a ground 2I4. Push-button switch 2" is the starting switch, and upon closing it when hand lever I9! is in its solid line position, current will flow from the round I8I through the solenoid I32, the generator G, the line I82, the switch I83, arm 2I3, contact 2I5, line 2I6, the push-button switch 2I I to the ground 2I4, thereby energizing the solenoid I32 and indexing the function drum I20, as well as the arm I53 of the distributor I 52. Although the various features of the improved control mechanism have been shown and described in detail to fully disclose one embodiment of the invention, it will be evident that numerous changes may be made in such details and certain features can be used without others, without departing from the principles of the invention.

What is claimed is:

1. Apparatus comprising in combination, a member; means for moving said member in either direction at any one of a plurality of speeds along a path; means for selecting the direction and speed of said member for successive movements along said path within a cycle of operation; an electrical bridge circuit adapted to be balanced when said member arrives at a pre-determined point in its path of travel; and means rendered effective upon the balancing of said bridge circuit for causing said selecting mean to select a succeeding direction and speed of said member.

2. Apparatus comprising in combination, a member; means for moving said member in either direction at any one of a plurality of speeds along a path; means for selecting the direction and speed of said member for successive movements along said path within a cycle of operation; an electrical bridge circuit including variable-impedance means adapted to be balanced when said member arrives at a pre-determined point in its path of travel; and means rendered effective upon the balancing of said bridge circuit for causing said selecting means to select a succeeding direction and speed of said member.

3. Apparatus comprising in combination, a member; means for moving said member in either directionat any one of a plurality of speeds along a pluralit of paths; means for selecting the path, direction and speed of said member forsuccessive movements thereof along said paths within a cycle of operation; an electrical bridge circuit adapted to be balanced when said member arrives at a pre-determined point in any of its paths of travel; and means rendered effective upon the balancing of said bridge circuit for causing said selecting means to select a succeeding path, direction and speed of said member.

4. Apparatus comprising in combination, a member; means for moving said member in either direction at any one of a plurality of speeds along a plurality of paths; means for selecting the path, direction and'speed of said member for successive movements thereof along said paths within a cycle of operation; an electrical circuit including an impedance bridge adapted to be balanced when said member arrives at a predetermined point in any of its paths;

and means rendered effective upon the balancing of said bridge circuit for causing said selecting means to select a succeeding path, direction and speed of said member when said member arrives at a pre-determined point in any of its paths of travel.

5. Apparatus comprising in combination, a member; means for moving said member in either direction at any one of a plurality of speeds along a, plurality of paths; means for selecting the path, direction and speed of said member for successive movements thereof along said paths within a cycle of operation; an electrical circuit including a variable-impedance bridge adapted to be balanced when said member arrives at a predetermined point in any of its paths; and means rendered effective upon the balancing of said bridge circuit for causing said selecting means to select a succeeding path, direction and speed of said member when said member arrives at a pre-determined point in any of its paths of travel 6. Apparatus comprising in combination, a member; means for moving said member in either direction at any one of a plurality of speeds along a plurality of paths; means for selecting the path, direction and speed of. said member for successive movements thereof along said paths within a cycle of operation; a biased detector circuit; a bridge circuit adapted to cooperate with said biased detector circuit, and adapted to be balanced when said member arrives at a pre-determined point in any of its paths of travel; and means rendered eiTective upon the balancing of said bridge circuit for causing said selecting means to select a succeeding path, direction and speed of said member.

7. Apparatus comprising in combination, a member; means for moving said member in either direction at any one of a plurality of speeds along a plurality of paths; means for selecting the path, direction and speed of said member for successive movements thereof along said paths within a cycle of operation; an electrical impedance bridge circuit including a source oi current at audio frequency; means for balancing said bridge circuit when said member arrives at a pre-determined point in any of its paths of travel; and means rendered effective upon the balancing 01' said bridge circuit for causing said selecting means to select a succeeding path, direction and speed of said member.

8. Apparatus comprising in combination, a member; means for moving said member in either direction along one or more paths at any one of a plurality of speeds any number of times within a cycle of operation; means adapted successively to be rendered effective to select the speed, path and direction of each motion of said member within said cycle of operation; an electrical bridge circuit including separate pre-settable impedance means for each motion of said member within said cycle; and separate impedance means for each path along which said member is adapted to be moved, responsive to the movement of said member and adapted to cooperate with any of said pre-settable impedance means when said member arrives at a pre-determined point in any of its paths of motion to cause said bridge to become balanced to render effective said selecting means to select the next succeeding path, direction and speed of motion of said member within said cycle of operation.

9. Apparatus comprising in combination, a member; means for moving said member in either direction along one or more paths at any one of a plurality of speeds any number of times within a cycle of operation; means adapted successively to be rendered effective to select the speed, path and'direction of each motion of said member within said cycle of operation; a capacitance bridge circuit including separate pre-settable means for each motion of said member within said cycle; and separate means for each path along which said member is adapted to be moved, responsive to the movement of said member and adapted to cooperate with any of said pre-settable means when said member arrives at a pre-determined point in any of its paths of motion to cause said circuit to render effective said selecting means to select the next succeeding path, direction and speed of motion of said member within said cycle of operation.

10. Apparatus comprising in combination, a member; either direction along one or more paths at any one of a plurality of speeds any number of times within a cycle of operation; means adapted successively to be rendered effective to select the speed, path and direction of each motion of said member within said cycle of operation; an electrical bridge circuit including separate pre-settable variable-capacitance means for each motion of said member within said cycle; and separate means for each path along which said member is adapted to be moved, responsive to the movement or said member and adapted to cooperate with any of said pre-settable variablecapacitance means when said member arrives at a pre-determined point in any of its paths of motion to cause said bridge to become balanced to render effective said selecting means to select the next succeeding path, direction and speed of motion of said member within said cycle of operation.

11. Apparatus comprising in combination, a member; means for moving said member in either direction along one or more paths at any one of a plurality of speeds any number of times within a cycle of operation; means adapted sucmeans for moving said member in path along which said member is adapted to be moved, responsive to the movement of said member and adapted to cooperate with any of said pre-settable impedance means when said member arrives at a pro-determined point in any of its paths of motion to cause said biased detector circuit to render effective said selecting means to select the next succeeding path, direction and speed of motion of said member within said cycle of operation.

12. Apparatus comprising in combination, a member; means for moving said member in either direction along one or more paths at any one of a plurality of speeds any number of times within a cycle of operation; means adapted suc cessively to be rendered effective to select the speed, path and direction of each motion of said member within said cycle of operation; an elec trical bridge circuit including a source of current at audio frequency and separate pre-settable impedance means for each motion of said member within said cycle; and separate impedance means for each path along which said member is adapted to be moved responsive to the movement of said member and adapted to cooperate with any of said pre-settable impedance means when said member arrives at a pre-determined point in any of its paths of motion to cause said circuit to render effective said selecting means to select the next succeeding path, direction and speed of motion of said member within said cycle of operation.

13. Apparatus adapted to produce a plurality of functions; a control member for said apparatus including a plurality of portions, each adapted selectively to be set for causing said apparatus to produce one of said functions; an electrical bridge circuit includin a plurality of impedance means, one for each of said portions, adapted to cooperate with other impedance means responsive to said functions at any point within the extent of said functions for balancing said bridge circuit; and a biased detector circuit acted upon by said bridge circuit for rendering effective the next succeeding portion of said control member.

14. Apparatus adapted to produce a plurality of functions; a control drum for said apparatus including a plurality of portions, each adapted selectively to be set for causing said apparatus to produce one of said functions; an electrical bridge circuit including a plurality of impedance means, one for each of said portions, adapted to cooperate with other impedance means responsive to said functions at an point within said functions for balancing said bridge c'rcuit; and a biased detector circuit acted upon by said bridge circuit for controlling means for indexing said drum to render effective successive of said porticns.

15. Apparatus adapted to produce a plurality of functions; a. control member for said apparatus including a plurality of portions, each adapted selectively to be set for causing said apparatus to produce one or said functions; an electrical bridge circuit including a plurality of capacitance means, one for each of said portions, adapted to cooperate with other capacitance means responl sive to said functions at any point within said functions for balancin said bridge circuit; and a biased detector circuit acted upon by said bridge circuit for rendering effective successive of said portions.

16. Apparatus adapted to produce a plurality of functions; a control member for said apparatu including a plurality of portions, each adapted selectively to be set for causing said apparatus to produce one of said functions; an electrical impedance bridge circuit including a plurality of manually-operable variable-impedance means, one for each of said portions; other variable-impedance means responsive to said functions at any point within said functions adapted to cooperate with any of said plurality of manually-operable impedance means for balancing said bridge circuit; and a biased detector circuit acted upon by said bridge circuit for rendering effective successive of said portions.

17. Apparatus adapted to produce a plurality of functions; a control member for said appa-, ratus including a plurality of portions, each\ adapted selectively to be set for causing said plurality of manually-operable impedance means;

' a distributor adapted selectively to connect each apparatus to produce one of said functions; an

electrical capacitance bridge circuit including a source of current at audio frequency and a plurality of manually-operable variable-capacitance means, one for each of said portions; other variable-capacitance meansresponsive to said functions at any point within said functions adapted to cooperate with any of said plurality of manually-operable capacitance means for balancing said bridge circuit; and a biased detector circuit acted upon by said bridge circuit for rendering effective successive of said portions.

18. Apparatus adapted to produce a plurality of functions; a control member for said apparatus including a plurality of portions, each adapted' selectively to be set for causing said apparatus to produce one of said functions; an electrical bridge circuit including a plurality of variable plate condensers, one for each of said portions, adapted to cooperate with means responsive to said functions at any point within said functions for balancing said bridge circuit; and a biased detector circuit acted upon by said bridge circuit for rendering effective successive of said portions.

19. Apparatus adapted to produce a plurality of functions; a control member for said apparatus including a plurality of portions, each adapted selectively to be set for causing said apparatus to produce one of said functions; an electrical bridge circuit including a plurality of variable plate condensers, one for each of said portions, adapted tov cooperate with a similar plate condenser responsive to said functions at any point within said functions for balancing said bridge circuit; and a biased detector circuit acted upon b said bridge circuit for rendering effective successive of said portions.

20. Apparatus adapted to produce a plurality of functions; a control member for said apparatus including a plurality of ortions, each adapted selectively to be set for causing said apparatus to produce on of said functions; an electrical bridge circuit including a source of current at audio frequency and a plurality of variable plate condensers, one for each of said portions; another variable plate condenser responsive to said functions at any point within said functions for balancing said bridge circuit; and a biased detector circuit acted upon by said bridge circuit for rendering effective successive of said portions.

21. Apparatus comprising in combination, a

of said impedance means into one leg of an electrical bridge circuit; -a biased detector circuit adapted to be acted upon by said bridg circuit; a member; means for moving said member; other impedance means responsive to the movement of said member adapted to cooperate with said manually-operable impedance means when said member arrives at a pre-determined point as dictated by the setting of said manually-operable impedance means for operating said biased detector circuit for energizing an auxiliary circuit; and means operated by said auxiliary circuit.

22. Apparatus comprising in combination, a plurality ofmanually-operable plate condenser means; a distributor adapted selectively to connect each of said condenser means into one leg of an electrical bridge circuit; a source of audio 0 frequency current impressed across said bridge circuit; a biased detector circuit adapted to be acted upon by said bridge circuit; a member; means for moving said member; separate plate condenser means responsive to the movement of said member adapted to cooperate with said manually-operable plate condenser means when said member arrives at a pre-determined point as dictated by the settin of said manuallyoperable plate condenser means for balancing said bridge circuit; means responsive to the balancing of said bridge circuit for operating said biased detector circuit to energize an auxiliary circuit; and means operated by said auxiliary circuit.

23. In a machine tool, a tool head adapted to be moved in either direction along a path of travel; pre-settable control means having a plu rality of stations, each adapted to be rendered effective by a step-by-step indexing mechanism for controlling the direction, rate and extent of movement of said head along said path; an electronic circuit adapted to cooperate with said presettable means; said pre-settable means being adapted to provide a predetermined signal voltage in said electronic circuit for each station to which it is indexed; means responsive to the movement of said tool head for nullifying said signal voltage; and means responsive to the null condition of said circuit for causing said presettable means to be indexed to its next succeeding station.

24. In a machine tool, a tool head adapted to be moved in either direction along a. plurality of paths; pre-settable control means having a plurality of stations, each adapted to be rendered effective by a step-by-step indexin mechanism for controlling the path, direction, rate and extent of movement of said tool head; an electronic circuit adapted to cooperate with said pre-settable control means and adapted to have impressed upon it predetermined signal voltages by said pre-settable control means for each station thereof; means responsive to the movement of said tool head for balancing said signal voltages; and means responsive to the balancing of said signal voltages for causing said pre-settable control means to be indexed to its next succeeding station.

ROBINSON D. BULLARD. JOHN H. SHERWOOD. PAUL M. GEIST.

(References on following page) 17 REFERENCES CITED Number The following references are of record in the 2'116593 file of this patent: UNITED STATES PATENTS 5 -2 31 75 Number Name Date 2,352,185 1,586,233 Anschutze-Kaempfe May 25, 1926 2,427, 1,879,388 Mershon Sept. 27, 1932 1,916,706 Wittkuhns et a1 July 4, 1933 2,002,353 Reinken May 21, 1935 10 Number 2,111,786 Knight Mar. 22, 1938 250,957

Name Date Bouvier et a1 May 10, 1938 Nessell Nov. 8, 1938 Garman Jan. 21, 1941 Laboulais Apr. 20, 1943 Bullard 3rd et a1. June 27, 1944 Bullard 3rd Sept. 16, 1947 FOREIGN PATENTS Country Date Great Britain Dec. 9, 1926 

